I've made a little tool in Construct to get details about your video hardware, which saves you looking up the specs of your computer. This thread will be linked to in tech support when we need to know your video hardware for a bug report or issue: if we've directed you here, run the program, and paste the output to your thread. Get it here:

Well I'm actually using a DirectX function to retrieve texture memory - I think some texture memory is mapped to system memory so you have more room for textures... I'm not sure how it works, it's a bit annoying it doesnt have much to do with physical VRAM.